Apparatus for adsorbing fuel vapor

Abstract

An apparatus for adsorbing fuel vapor having a fuel vapor inlet hole communicating to a fuel tank, a mixed gas outlet hole communicating to the intake passage for internal combustion engine, an inlet hole for the desorbent air communicating to the atmospheric air and an adsorbent for adsorbing fuel vapor and by using, as to the adsorbent which is at least partially foamed body of active charcoal constituting a three-dimensional network cell structure having an inner communicating space between granular active charcoals.

What is claimed is: 
     
       1. An apparatus for adsorbing fuel vapor comprising: a container having side walls and opposed ends; a fuel vapor inlet in one of said ends for introducing the fuel vapor into the container; a gas outlet in the other if said ends for taking the air-fuel mixture out from the container; and air inlet for introducing the air into the container for desorbing the fuel vapor; an adsorbent being set in the container, for adsorbing the fuel vapor said adsorbent containing a foamed body of active charcoal constituting a three-dimensional network cell structure having an inner communicating space; and a thin sleeve of active charcoal snugly surrounding the foamed body between the latter and said side walls.   
     
     
       2. An apparatus according to claim 1, wherein said adsorbent is a foamed body of active charcoal obtained by dipping a polyurethane foam constituting a three-dimensional network cell structure having a communicating space having no cell membrane and composed only of skeleton into a mixed fluid comprising a powdered active charcoal, a powdered lignin, water and methyl cellulose, drying the polyurethane foam, repeating these procedures to let the charcoal powder, lignin powder and methyl cellulose adhere thereto and then firing the dipped product. 
     
     
       3. An apparatus according to claim 2, wherein said adsorbent is a foamed body of active charcoal obtained by firing said dipped product in which the amount of mixed fluid comprising powdered active charcoal, powdered lignin, water and methyl cellulose adhering to polyurethane foam is 0.5 g per 1 cm 3  of polyurethane foam based on the dried residue of said mixed fluid. 
     
     
       4. An apparatus according to claim 2, wherein said adsorbent is a foamed body of active charcoal obtained by firing said dipped product at a temperature of 600°-1,000° C. 
     
     
       5. An apparatus according to claim 2, wherein said adsorbent is a foamed body of active charcoal obtained by dipping polyurethane foam into a mixed fluid comprising powdered active charcoal, powdered lignin, water and methyl cellulose wherein the composition ratio of respective components is 100:150:80:11 (ratio by weight), drying the polyurethane foam to let the components adhere thereto and then firing it.